Cone Traits Research Articles

Taxonomic Revision of Genus Ephedra Tourn. ex L. in Egypt with Intra-Gender Diversity in Morphometric Traits and Fatty Acid Composition.

The genus Ephedra Tourn. ex L. (Ephedraceae) still exhibits taxonomic complexity that has not yet been resolved. This study aimed to determine the taxonomic identity of the Ephedra species in Egypt and identify the fatty acid profile and its diversity at the gender level as a taxonomic tool for specimens lacking reproductive cones. The current study provides a pioneering approach that distinguishes Ephedra species at the gender level. A total of 120 fresh individuals were collected from 20 locations representing different habitats where Ephedra plants grow in Egypt. In addition, herbarium specimens were deposited in Egyptian herbaria. The studied morphological traits included 30 vegetative characteristics and 72 traits of the reproductive organs of both genders. The fatty acid content was measured using gas-mass chromatography (GC-Mass). The taxonomic revision revealed that the Genus Ephedra was represented in the Egyptian flora by five species, Ephedra alata in section Alatae and E. aphylla, E. ciliata, E. foemina, and E. pachyclada in section Ephedra. South Sinai hosts these five species and represents the center of diversity for this genus in Egypt. The vegetative characteristics were subjected to principal component analysis (PCA), which revealed a distinct separation of the five studied species. Similarly, the cone traits treated by hierarchical clustering revealed intra-gender variations. The taxonomic key was developed based on the morphological traits to distinguish the studied species at the gender level. In total, 51 fatty acids were identified from the studied species and grouped as 18 saturated, 16 monounsaturated, and 17 polyunsaturated fatty acids. In the absence of reproductive cones, the lipid content and fatty acid composition of the vegetative parts displayed significant interspecific and intra-gender variations. Therefore, fatty acids can be used to efficiently identify the studied species when they lack reproductive cones. This study proved the efficacy of a multidisciplinary approach to identify Ephedra species at the gender level and recommends this trend for future studies of this genus.

Spatial and Temporal Variation in the Antagonistic and Mutualistic Interactions among Seed Predator Arthropods, Seed-Dispersing Birds, and the Spanish Juniper.

Plants interact with both antagonistic and mutualistic animals during reproduction, with the outcomes of these interactions significantly influencing plant reproductive success, population dynamics, and the evolution of plant traits. Here, we investigated the spatial and temporal variations in the interactions between Juniperus thurifera, its seed-dispersing birds, and three specific arthropod species that attack the fleshy cones during the predispersal period. We assessed how plant traits affect levels of cone damage by arthropods and seed dispersal by birds, the occurrence of competition among arthropod species, and the impact of seed predators on the activity of frugivores. Plant traits, cone damage by arthropods, and seed dispersal by birds showed spatiotemporal variability. Fluctuation in cone abundance was the leading factor determining damage by arthropods and bird dispersal with a secondary role of cone traits. Large crops satiated predispersal seed predators, although the amount of frugivory did not increase significantly, suggesting a potential satiation of bird dispersers. Crop size and cone traits at individual trees determined preferences by seed predator species and the foraging activity of bird dispersers. Competition among arthropods increased during years of low cone production, and seed predators sometimes negatively affected bird frugivory. High supra-annual variations in cone production appear to be a key evolutionary mechanism enhancing J. thurifera reproductive success. This strategy reduces the impact of specialized seed predators during years of high seed production, despite the potential drawback of satiating seed dispersers.

Cone allometry and seed protection from fire are similar in serotinous and nonserotinous conifers.

Serotiny is an adaptive trait that allows certain woody plants to persist in stand-replacing fire regimes. However, the mechanisms by which serotinous cones avoid seed necrosis and nonserotinous species persist in landscapes with short fire cycles and serotinous competitors remain poorly understood. To investigate whether ovulate cone traits that enhance seed survival differ between serotinous and nonserotinous species, we examined cone traits in 24 species within Pinaceae and Cupressaceae based on physical measurements and cone heating simulations using a computational fluid dynamics model. Fire-relevant cone traits were largely similar between cone types; those that differed (e.g. density and moisture) conferred little seed survival advantage under simulated fire. The most important traits influencing seed survival were cone size and seed depth within the cone, which was found to be an allometric function of cone mass for both cone types. Thus, nonserotinous cones should not suffer significantly greater seed necrosis than serotinous cones of equal size. Closed nonserotinous cones containing mature seeds may achieve substantial regeneration after fire if they are sufficiently large relative to fire duration and temperature. To our knowledge, this is the most comprehensive study of the effects of fire-relevant cone traits on conifer regeneration supported by physics-based fire simulation.

Detailed Seed Cone Morpho-Anatomy Provides New Insights into Seed Cone Origin and Evolution of Podocarpaceae; Podocarpoid and Dacrydioid Clades.

The study of reproductive morphology and trait evolution provides a vital insight to understand the evolutionary history of plants. The conifer family Podocarpaceae has a remarkable diversity of seed cones, with distinct morphology among the genera and with conifers in general. However, we lack a good understanding of the seed cone morpho-anatomy and trait evolution of Podocarpaceae. We investigated detailed seed cone morpho-anatomy using staining and sectioning techniques to clarify the anatomical, morphological diversity and evolution of functional traits. The presence of a fleshy receptaculum is a characteristic feature of both clades. However, species of Retrophyllum, Afrocarpus and some species of Nageia and Podocarpus form a fleshy sarcotesta-like seed coat, lacking a fleshy receptaculum. The ancestral state reconstructions show a shift between and sometimes within the genus. Although both clades demonstrate fleshiness as an ancestral trait, the shift in fleshy structures provides evidence for complex multiple evolutions of fleshy morphologies. These seed cone traits (e.g., fleshiness and size), along with the broad, flattened and well-adapted (leaf dimorphism) foliage in both clades, are largely congruent with efficient light harvesting and bird dispersal. These traits make these two clades well adapted to their environment, when growing in communities including tall and broad-leaved angiosperms (closed-canopy angiosperm forests), compared to other podocarps, making them more successful in achieving a wider distribution and species richness.

Seed Distribution and Phenotypic Variation in Different Layers of a Cunninghamia Lanceolata Seed Orchard

The phenotypic characteristics of forest seeds are the basis of germplasm innovation, genetic improvement, and biological research, and they also are the reference for the development of seed orchards. In this study, we analyzed seed quantity characteristics, phenotypic differentiation, and variation patterns in three seed-bearing clones from different crown layers of the Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) orchard located in Fujian Province, China. We divided the clones into six layers according to crown height and the sunny and shady sides, 14 phenotypic characteristics, and five quality indexes, and we measured the germination rate of seeds. The rate of seeds filled with tannin-like substance in the upper sunny layer was low, but it was high in the lower shady layer. The germination rate was highest in the upper sunny layer and lower in the middle and lower shady sides. Values of most of the 14 phenotypic traits tested differed significantly among clones and layers. The average value of the phenotypic differentiation coefficient was 81.16%, indicating that variation among clones explained most of the total phenotypic variation. The repeatability of the 14 phenotypic traits was high (R > 0.80), indicating that these traits are highly heritable. The phenotypic characteristics of cones and seeds varied from 6.86% to 129.51%. The 14 phenotypic traits exhibited different degrees of correlation, and seed weight, seed circumference, seed width, and seed area can be used to predict other seed traits. However, the correlations between cone traits were not strong. Our results show that when establishing a dwarfing Chinese fir seed orchard, the distribution and variation of seeds in different crown layers of clones should be considered, and clones with more cones in the lower crown layer should be selected as parents.

Detailed seed cone morpho-anatomy of the Prumnopityoid clade: an insight into the origin and evolution of Podocarpaceae seed cones.

Seed cone traits are significant for understanding the evolutionary history of conifers. Podocarpaceae has fleshy cones with a distinct morphology compared with other conifers. However, we have a poor understanding of the seed cone morphology of the Prumnopityoid clade and within Podocarpaceae. This study presents detailed seed cone morpho-anatomy and the evolution of fleshy structures traits in the Prumnopityoid clade. We investigated the detailed seed cone morpho-anatomy of selected species from the nine genera using the histological method. The evolution of morpho-anatomical traits was assessed using ancestral state reconstruction methods. The Prumnopityoid clade has evolved fleshy seed cones using different functional structures (e.g. aril, epimatium, bracts or receptaculum) and fleshiness is an ancestral trait in the clade. An epimatium is present in all genera except Phyllocladus, but with different structural morphologies (e.g. a fleshy asymmetrical cup-like epimatium or an epimatium that is fused with the integument, forming a fleshy sarcotesta-like seed coat). In all species with fleshy sarcotesta-like seed coats, the endotesta is hard and woody, forming a sclerotesta-like structure and the epimatium and exotesta are fused, forming a fleshy sarcotesta-like structure. This study highlights that the Prumnopityoid clade has an amazing diversity of structures and complex evolutionary patterns. Fleshiness is an ancestral trait of the clade and has been achieved via diverse evolutionary pathways and structures. This clade has four distinct seed cone types, i.e. drupe-like, receptaculate, arilloid and dacrydioid cones, based on morpho-anatomical structures and traits. The macrofossil record also demonstrates the presence of several structures and traits.

Juniperus excelsa s. str. in crimea – differentiation and history inferred from genetic and morphological markers

Abstract Juniperus excelsa s. str. (Greek juniper) in Crimea is a relic species on the limits of its range, and represents the Mediterranean flora in the Sub-Mediterranean part of the peninsula. Its origin and history in this area remains unresolved. We aimed to analyze phylogeny and potential demographic expansion of the juniper in the Crimea as well as to study its morphological differentiation. We analyzed plant material from 59 trees inhabiting eight populations. Genetic variation assessments were based on the four non-coding chloroplast DNA (cpDNA) fragments and the nuclear internal transcribed spacer region ITS1-5,8S-ITS2 (ITS). To examine the morphological differentiation, eight measured/counted traits of cones, seeds, and shoots were chosen and eight ratios were calculated. Morphological parameters were compared using ANOVA, Student’s t test, discrimination analysis and Kruskal-Wallis and U Mann-Whitney tests. Two cpDNA fragments were polymorphic and, in total, 10 cpDNA haplotypes were found. Haplotype diversity (Hd) ranged from 0.0 to 0.9. Based on both cpDNA and ITS sequences variation, phylogenetic analyses revealed a close relationship of the Crimean junipers to the individuals from other parts of the species range. In general, our molecular results confirmed the low level of genetic differentiation of J. excelsa individuals inhabiting different parts of the species range, likely resulting from a common ancestry. Only slight morphological differences were found between populations with different geographic location or habitat. The analyzes showed the distinctness of the populations from the southern part of the coast. Some unique morphological and molecular features of southern coastal populations imply that they are remnants of Late Pleistocene abundant forests. We suggest that the recent fragmentation of the Juniperus populations in the Crimean Peninsula could have arisen during the Atlantic period of the Holocene.

Morpho-anatomical affinities and evolutionary relationships of three paleoendemic podocarp genera based on seed cone traits.

The three relict genera Pherosphaera, Microcachrys and Saxegothaea in Podocarpaceae produce quite distinct seed cone types in comparison with other genera and do not form a clade along with Acmopyle. The detailed seed cone morpho-anatomy of these three relict genera and affinities with other podocarps are poorly known. This study aims to understand the seed cone morpho-anatomy and affinities among these three disjunct relict genera and with other podocarps. We comparatively analysed the seed cone morpho-anatomical traits of the three podocarps genera and used ancestral state reconstruction to understand the evolution of these traits. We described the seed cone morpho-anatomical structures of the three relict genera in detail. The three genera produce aggregated multiovulate cones. Both Microcachrys and Saxegothaea have an asymmetrical free cup-like epimatium. Both species of Pherosphaera lack an epimatium. The ancestral state reconstruction implies that the presence of an epimatium is an ancestral trait in podocarps and is independently lost in Pherosphaera and Phyllocladus. The seed cones are fleshy in Microcachrys and non-fleshy in Saxegothaea and Pherosphaera. The seed cone macrofossils of both extinct and living podocarps also show the presence of an epimatium and fleshiness in podocarps. Altogether, the morpho-anatomy suggests that Pherosphaera, Microcachrys and Saxegothaea present affinities with each other and other podocarps, but the reconstruction of the ancestral seed cone in Podcarpaceae is quite complex due to multiple convergent evolutions of several structures. These structures (e.g. epimatium, aril and receptaculum) are of low taxonomic value but of great evolutionary and ecological significance, and are responsive adaptations to ever-changing environmental conditions.

Are There Any Traces of Pinus uliginosa in the Stołowe Mountains Outside the Wielkie Torfowisko Batorowskie and Błędne Skały?

AbstractPinus sylvestris(Scots pine) and taxa from theP. mugo(mountain pine) complex hybridize in contact zones producing morphologically-intermediate fertile hybrids. However, the hybrid specimens sometimes express only theP. sylvestrisphenotype. Such cryptic hybrids were detected amongP. sylvestrisandP. uliginosain the western part of Błędne Skały in the Stołowe Mountains, where the pines grow on the tops of sandstone rocks and phenotypically resembleP. sylvestris,P. uliginosa, andP. mugo. Hybrids with theP. sylvestrisphenotype could be potentially present in other relic populations of this species in these mountains. During the present study, the hybrids were identified only in the area of Błędne Skały based on chloroplast and mitochondrial markers, morphological differentiation of various needle and cone traits, and phenotype assessments of the trees during sampling. These hybrids included three cryptic hybrids ofP. sylvestris×P. mugowith theP. sylvestrisphenotype and one displaying the phenotype ofP. uliginosa. The other populations analyzed represented Scots pine with no evidence of hybridization withP. uliginosaand/orP. mugo. Biometric data on the cone and needle morphology also suggest possible hybridization within theP. mugocomplex on Błędne Skały. The results indicate that hybridization takes place in this population but not in neighboring populations despite the possible connection by pollen-mediated gene flow.

Assessment and Models of Insect Damage to Cones and Seeds of Pinus strobiformis in the Sierra Madre Occidental, Mexico.

Insect damage to cones and seeds has a strong impact on the regeneration of conifer forest ecosystems, with broader implications for ecological and economic services. Lack of control of insect populations can lead to important economic and environmental losses. Pinus strobiformis is the most widespread of the white pines in Mexico and is widely distributed throughout the mountains of northern Mexico. Relatively few studies have examined insect damage to the cones and seeds of these pines, especially in Mexico. In this study, we therefore analyzed insect damage to cones and seeds of P. strobiformis in Mexico by using X-ray and stereomicroscopic analysis. The specific objectives of the study were (a) to characterize insect damage by measuring external and internal cone traits, (b) to assess the health of seeds and cones of P. strobiformis in the Sierra Madre Occidental, Mexico, and (c) to estimate the relative importance of the effects of different environmental variables on cone and seed damage caused by insects. We found that 80% of P. strobiformis seeds and 100% of the tree populations studied had damage caused by insects. Most seeds were affected by Leptoglossus occidentalis, Tetyra bipunctata, Megastigmus albifrons, and the Lepidoptera complex (which includes Apolychrosis synchysis, Cydia latisigna, Eucosma bobana, and Dioryctria abietivorella). The cones of all tree populations were affected by some type of insect damage, with Lepidoptera causing most of the damage (72%), followed by Conophthorus ponderosae (15%), the hemipteran L. occidentalis (7%), and the wasp M. albifrons (6%). The proportion of incomplete seeds in P. strobiformis at the tree level, cone damage by M. albifrons and seed damage in L. occidentalis were associated with various climate and soil variables and with crown dieback. Thus, cone and seed insect damage can be severe and potentially impact seed production in P. strobiformis and the reforestation potential of the species. The study findings will enable managers to better identify insects that cause damage to cone and seeds. In addition, identification of factors associated with damage may be useful for predicting the levels of insect predation on seeds and cones.

Limited evidence for a consistent seed mass‐dispersal trade‐off in wind‐dispersed pines

Abstract Much of the variation in dispersal potential among seeds of different plant species has been related to a putative trade‐off between dispersal potential and seed mass. Yet to date there are few taxonomically controlled comparisons that explore the generality of this relationship across and within multiple species. We measured the seed mass and dispersal traits across multiple pine species that encompassed a 100‐fold range in seed mass. We expected that for the larger seeded species, the resource investment required in the cone to house seeds and their wings may constrain dispersal potential. We examined the relative roles of samara and cone traits in determining the terminal velocity, and investigated how the relative investment of resources in cone structure related to seed mass and samara dispersal traits. Finally, we examined the partitioning of variation in seed mass and terminal velocity within and among individuals of each species. We found a strong positive relationship between seed mass and samara terminal velocity across all 12 species; however, this seed mass‐dispersal trade‐off was only significant within two of our species. For most species, wing loading was the most important trait determining samara terminal velocity. Across species, increases in cone investment were associated with heavier seeds with longer wings but higher terminal velocities, while within‐species increases in cone investment were associated with decreases in terminal velocity. The majority of the variation in terminal velocity occurred within individual trees, while seed mass variation mostly occurred among trees and may therefore be subject to stronger selection pressure. Synthesis. We have found strong support for a trade‐off between seed mass and dispersal potential across a wide range of wind‐dispersed Pinus species. Importantly, we show that this trade‐off is largely absent within species, potentially reducing selective pressure. This may be largely due to the relationships between cone investment and samara traits, whereby increases in cone investment result in a proportionally greater increase in wing size than seed mass. Where resources are limited, investment in seed mass may be prioritized over dispersal.

Enhanced seed defenses potentially relax selection by seed predators against serotiny in lodgepole pine.

Serotiny, the retention of seeds in a canopy seed bank until high temperatures cause seeds to be released, is an important life history trait for many woody plants in fire‐prone habitats. Serotiny provides a competitive advantage after fire but increases vulnerability to predispersal seed predation, due to the seeds being retained in clusters in predictable locations for extended periods. This creates opposing selection pressures. Serotiny is favored in areas of high fire frequency, but is selected against by predispersal seed predators. However, predation also selects for cone traits associated with seed defense that could reduce predation on serotinous cones and thereby relax selection against serotiny. This helps explain the elevated defenses in highly serotinous species. However, whether such interactions drive variation in seed defenses within variably serotinous populations has been studied rarely. We investigated the effects of phenotypic selection exerted by red squirrel (Tamiasciurus hudsonicus) predation on Rocky Mountain lodgepole pine (Pinus contorta latifolia) seeds. Squirrels preferentially harvested cones with more and larger seeds, indicating a preference for a higher food reward. We found evidence for stronger selection on trees with serotinous cones, which presumably accounts for the elevated defenses of and lower predation on serotinous compared to non‐serotinous cones. Lower levels of predation on serotinous cones in turn lessen selection against serotiny by squirrels. This has important implications because the frequency of serotiny in lodgepole pine has profound consequences for post‐fire communities and ecosystems widespread in the Rocky Mountains.

Cones structure and seed traits of four species of large-seeded pines: Adaptation to animal-mediated dispersal.

Seed dispersal selection pressures may cause morphological differences in cone structure and seed traits of large‐seeded pine trees. We investigated the cone, seed, and scale traits of four species of animal‐dispersed pine trees to explore the adaptations of morphological structures to different dispersers. The four focal pines analyzed in this study were Chinese white pine (Pinus armandi), Korean pine (P. koraiensis), Siberian dwarf pine (P. pumila), and Dabieshan white pine (P. dabeshanensis). There are significant differences in the traits of the cones and seeds of these four animal‐dispersed pines. The scales of Korean pine and Siberian dwarf pine are somewhat opened after cone maturity, the seeds are closely combined with scales, and the seed coat and scales are thick. The cones of Chinese white pine and Dabieshan white pine are open after ripening, the seeds fall easily from the cones, and the seed coat and seed scales are relatively thin. The results showed that the cone structure of Chinese white pine is similar to that of Dabieshan white pine, whereas Korean pine and Siberian dwarf pine are significantly different from the other two pines and vary significantly from each other. This suggests that species with similar seed dispersal strategies exhibit similar morphological adaptions. Accordingly, we predicted three possible seed dispersal paradigms for animal‐dispersed pines: the first, as represented by Chinese white pine and Dabieshan white pine, relies upon small forest rodents for seed dispersal; the second, represented by Korean pine, relies primarily on birds and squirrels to disperse the seeds; and the third, represented by Siberian dwarf pine, relies primarily on birds for seed dispersal. Our study highlights the significance of animal seed dispersal in shaping cone morphology, and our predictions provide a theoretical framework for research investigating the coevolution of large‐seeded pines and their seed dispersers.

Variation in cone and seed traits in a clonal seed orchard of red pine (Pinus koraiensis Sieb. et Zucc.)

ABSTRACTPrevious studies on cone/seed traits of conifer seed orchards have focused on genetic variation, while non-genetic variation has rarely been investigated. This study examined the variation of cone/seed traits in a red pine clonal seed orchard in 2008 and 2018. The registered cone traits included size, weight, the number of seeds-cone, number of scales-cone and number of cones-tree and seed traits included size, weight, kernel weight and shell thickness. For cone traits other than cone size in 2018, which were under strong genetic control, the variation was largely and similarly contributed by interramet and intercone variations. For seed traits, over 90% of the variation was due to non-genetic factors, with contributions from interseed intertree > intercone. While heritability estimates for cone size were high, those for other cone traits and all seed traits were low on broad-sense basis (0.10) but moderate on clonal mean basis (0.35). Genetic correlations between cone or seed traits were positively moderate to strong other than the number of cones-tree, which correlated negatively with all other cone traits. The genetic correlations between cone and seed traits were weak, paired with mixed signs. The implications of these findings to manage seed orchards or advanced breeding were discussed.

Clonal variations in cone, seed and nut traits in a Pinus koraiensis seed orchard in Northeast China

Korean pine (Pinus koraiensis Siebold & Zucc.) in Northeastern China has been genetically improved to increase seed yields in addition to timber. To assess seed yield variability and select highly productive clones, 14 cone, seed and nut traits were measured and analyzed. Variance analysis showed that all clones were significantly different in various traits (P < 0.01). Phenotypic coefficients of variation and repeatability of traits ranged from 9.1 to 34.4% and from 27.5 to 97.7%, respectively. Except for the cone layer and cone seed numbers, the other traits were positively or negatively correlated. Three principal components were identified. Seed and nut traits were the most important traits in the first principal component, and cone traits more important in the second. Using correlation and principal component analyses, cone number and other traits were selected to evaluate materials. Twenty-two clones were selected using a selection rate of 10% based on cone number independently or other combined traits. The genetic gain for different traits ranged from 6.2 to 24.3%. The selected elite clones can supply seedlings for reforestation and the selection method can provide a theoretical basis for selection in other conifer species.

Genetic Variation in Growth and Cone Traits of Pinus Koraiensis Half-Sib Families in Northeast China

Genetic parameters were evaluated for growth and cone characteristics (tree height, diameter at breast height, volume, cone number, thousand seeds weight and single cone seeds weight) on 86 half-sib families of Pinus koraiensis aged 31 years. Analyses of variance revealed significant differences (p < 0.001) in all growth and cone traits among families while no significant differences were detected among blocks and the interaction between blocks and families. The average family values for growth traits were 17.22 m, 8.67 cm and 0.43 m3 for tree height, diameter at breast height and volume, respectively. The average cone number, thousand seeds weight and single cone seeds weight were 17.57, 748.91 g and 77.25 g, respectively. Genotypic additive variance and phenotypic variances ranged from 0.00009 to 3.820 and from 0.0005 to 23.066, while genotypic and phenotypic coefficients of variation ranged from 2.693% to 37.196% and 4.963% to 60.595%, respectively. Heritability at the individual and family level ranged from 0.152 to 0.215 and 0.611 to 0.862, respectively. Growth traits were significantly positively correlated with each other, but cone traits showed a weak correlation with growth traits. Based on 10% selection rate, nine families each were selected as elite materials in terms of high performance in volume and cone numbers, with 22.16% and 43.82% genetic gain in volume and cone number, respectively. These results provide beneficial information to select excellent families and establish orchards of P. koraiensis from improved seeds.

DNA Barcoding Identifies Juniperus oxycedrus subsp. macrocarpa in Derna Region, East Libya

Many methods are accessible that apply diverse criteria for the reasons of identifying taxonomic specialization depending on DNA sequencing information. It is crucial for the studies of taxonomy and biodiversity using DNA barcode technology to fast and accurately make species identification in the forests. According to the Encyclopedia of Earth, many wonderful and rare plants are destroyed. In the tropics and subtropics, numerous evergreen conifers are jeopardized. These plants grow in remote places of our planet, which are inaccessible. It merits referring to that Juniperus spp. an imperative part of Mediterranean arid and semi-arid biological communities. Juniperus oxycedrus subsp. macrocarpa is a rare woody species found in Jebel Al-Akhdar, Libya in only one peripheral site north-west Derna. A robust analysis presented based on using morphological traits of needles, seeds and cones, and DNA technology. Along these lines, jeopardized plant populations could be recognized more effectively. This study universality of tree species DNA barcodes. such as the rbcL and matK plastid markers, and examined their abilities of species identification. The morphological and genetic results strongly support the recognition of J. macrocarpa at the subspecies J. oxycedrus.

Geographic variation of Pinus heldreichii Christ from the Western Balkans based on cone and seed morphology

Pinus heldreichii (Bosnian pine) is a Balkan-Apennine endemic and relict pine species that inhabits high mountains in the Mediterranean and sub-Mediterranean regions. Nineteen populations of P. heldreichii from the Western Balkans encompassing 187 individual trees were examined to evaluate morphological variation, a rarely studied aspect of the species. Univariate and multivariate statistics were applied in order to assess the variation of morphological traits of cones and seeds, evaluate the relationships among the sampled populations and verify geographic differentiation in the Dinaric Alps versus Scardo-Pindic mountains. The observations of P. heldreichii covering the populations from the western margins and the centre of the species distribution range indicated a morphological variation among populations and their geographic structure. In general, the southern populations (Scardo-Pindic group) had lower values for the most of morphological traits than the northern ones (Dinaric group). The observed geographic differences between these populations exhibit a north-western to south-eastern gradient, with a few inconsistencies. The southernmost sampled population, Tomorr in Albania, showed remarkable morphological divergence from the other studied populations and appeared to be a distinct morphological group. The pattern of morphological variation in Bosnian pine most likely resulted from multiple effects of long-term isolation and fragmentation in high mountain systems, adaptation to extreme environments and human disturbances.

Семеношение и структура шишек у клонов мутационных ведьминых метел кедра сибирского

Mutational witches’ broom (WB) is a fragment of tree crown with abnormal morphogenesis, including slow growth, abundant branching, reduced apical dominance and often abundant seed production. Mutational WBs are the main source of ornamental dwarf grafting conifer cultivars. Siberian stone pine, like other conifers, is capable of forming mutational WBs. Inorder to reveal how the mutation affects the development of WB cones an analysis of the cone yield and cone size and structure in 20 WB clones was made, and they were compared with a mean normal Siberian stone pine cone with length 9 cm, width 6 cm, 57 seeds per cone and the proportion of the medial fertile zone 39.1–60.3% of the total number of scales. WB clones had a different number of cones. Thirteen-year old clones had 13 cones in average. All cone traits varied greatly among the WB clones. Three clones had shortest cones, their length was less than 3 cm. Two of the clones also had the smallest diameter, 2.3 and 2.2 cm, respectively. Four clones had relatively large cones, longer than 4 cm, and diameter 3.4 cm. The fertile zone in the cones of WB clones was from 27.8% to 55.6% from the total number of scales, i.e. only slightly smaller than that in normal cones. The cones contained 40–60 ovules, which gave rise to less than 20 seeds in 20% of the clones, and more than 40 seeds per cone in 15% of the clones, which is a third less than that in normal Siberian stone pine trees. The number of aborted seeds after pollination in cones was almost not high for all clones, however, for some, the proportion of aborted seeds was up to 30% of the total number of seeds per cone. Thus, the cones in WB clones were 2–3 times smaller, and they were generally inferior to normal Siberian stone pine cones, but the yield in WB clones was quite high. At the same time, the WB clones were highly variable in yield and cone quality. Only individual clones with good yield and relatively large cones can be promising for breeding as nut-bearing cultivars. Due to the negative WB crown density on the number and size of their cones, in most cases, the presence and abundance of cones can only serve as an additional feature that enhances the ornamental value of dwarf graft cultivars of Siberian stone pine. At the same time, all WB clones were fertile and could be used for cross-breeding and further selection work.For citation: Polyakova O.I., Zhuk Е.А., Goroshkevich S.N. Cone production and cone structure in the clones from mutational witches’ brooms of Siberian stone pine. Lesnoy Zhurnal [Forestry Journal], 2019, no. 5, pp. 25–34. DOI: 10.17238/issn0536-1036.2019.5.25Funding: This work is supported by the Russian Science Foundation under grant no. 18-16-00058. The article is published within the framework of implementation of the scientific journals development program in 2019, based on proceedings of XIX International conference of the young scholars “Forests of Euro-Asia – The Southern Ural” (August 25–30, 2019. Chelyabinsk).

Phenotypic variation of generative signs of different reproductive types of Pseudotsuga menziesii (Mirb.) Franco in urban environment (in the forest-steppe zone)

The average values and variability amplitude of morphological characters and reproductive traits of cones have been determined under the introduction of Pseudotsuga menziesii (Mirb.) Franco trees of different reproduction types. It is shown that the average indicators of the most signs correspond to the control in urban conditions. The level of signs variability is close to control ones, or increased in trees of female and mixed types. The possibility of phenotypic selection of trees of different reproduction types according to their stability in the urban environment is considered, as follows from the variability level of generative sphere parameters.